When the current in a toroidal solenoid is changing at a

rate of $0\mathrm{.}0260$ A$>$s$,$ the magnitude of the induced emf is $12\mathrm{.}6$ mV$.$

When the current equals $1\mathrm{.}40$ A$,$ the average flux through each

turn of the solenoid is $0\mathrm{.}00285$ Wb$.$ How many turns does the

solenoid have?